added ShowInsert.create_instance() hook
added ShowInsert.create_instance() hook

lsaffre/lino,lino-framework/lino,lino-framework/lino,lino-framework/lino,lsaffre/lino,lsaffre/lino,lsaffre/lino,lsaffre/lino,lino-framework/lino,lino-framework/lino